1. Field of the Invention
The present invention relates to a camera which includes a recording medium in which an image obtained during an exposure interval can be electronically developed.
2. Description of Related Art
There are many known photographic materials in which an optical image obtained during an exposure interval can be electronically developed. For example, in Japanese Unexamined Patent Publication No. 5-2280, a recording medium is disclosed which is comprised of an electrostatic data recording medium and an electric charge holding medium in combination. According to the above-noted document, the recording medium, which can be electronically developed, and a camera using the same are referred to as an electronic development type recording medium and an electronic development type camera, respectively.
In the electronic development type recording medium disclosed in JPP 5-2280, the electrostatic data recording medium is provided with a photoconductive layer and an inorganic oxide layer, and the charge holding medium is provided with a liquid crystal display element. In this arrangement, if the electrostatic data recording medium is exposed while a voltage is applied between the electrostatic data recording medium and the charge holding medium, electric charges, corresponding to the quantity of light to be incident thereupon, are produced. The intensity of an electric field to be applied to the liquid crystal display element, that is opposed to the electrostatic data recording medium, varies depending on the electric charges produced, and hence, an image corresponding to the distribution of the quantity of light is displayed in the liquid crystal display element. Namely, the image recorded on the electrostatic data recording medium, as a latent image, is immediately developed to be displayed in the liquid crystal as a visible image.
Preferably, a dispersive liquid crystal display element, as disclosed in Japanese Unexamined Patent Publication No. 5-150251, is used as the liquid crystal element for the electronic development type recording medium. In the dispersive liquid crystal display element, the visible image formed on the liquid crystal display element, by the application of the electric field thereto, can be held even after the electric field has been removed. Consequently, the electronic development type recording medium can be stored in much the same way as conventional slide films.
In the electronic development type recording medium disclosed in JPP 5-2280, the recorded image can be erased by initializing the orientation of the liquid crystal, and hence, the same electronic development type recording medium can be repeatedly used. In spite of this advantage, however, there is a possibility that an electronic development type recording medium which already has an image recorded on it (exposed), may be used to re-record a new image (re-exposure). If a re-exposure process is to take place, the intended new image cannot be obtained without the recorded image first being erased.